In the recent years, 3D stereo image display has become a development direction of the industry to provide a better visual perception to viewers. Different from a normal display, the 3D stereo image display needs to respectively provide proper images to the left eye and the right eye of a viewer such that the viewer may then form a mental image of the 3D stereo image.
In the 3D stereo display technology, the 3D stereo display associated with a time sequence is considered quite mature. That is, images of the left eye and images of the right eye are alternately displayed on the basis of a time sequence so that the eyes of the viewer perceive the left-eye images and the right-eye images alternately. More particularly, the left eye of the viewer only perceives the left-eye images and the right eye of the viewer only perceives the right-eye images. For example, a pair of 3D glasses, having a left-eye shutter and a right-eye shutter, associated with a display capable of alternately displaying the left-eye images and the right-eye images, can provide 3D stereo images to the viewer.
FIG. 1 is a schematic diagram of a display timing control of 3D images displayed by an LCD display and a pair of 3D glasses. Referring to FIG. 1, the LCD display alternately displays left-eye images and right-eye images. Since the LCD display is a hold-type display, each of the pixels of the LCD display displays current pixel data continuously. Therefore, as shown in the diagram, during updating a display image of the LCD display with a left-eye image, the display image actually contains not only an updated left-eye image, but also a right-eye image that is not yet updated. Likewise, during updating the display image of the LCD display with a right-eye image, the display image actually contains not only an updated right-eye image, but also a left-eye image that is not yet updated. In order to avoid crosstalk, the pair of 3D glasses is only correspondingly switched to an open state during vertical blanking intervals (VBIs). That is, a left-eye shutter of the 3D glasses is opened during the VBI after the left-eye images have been updated, and when the current display image begins to be updated with the right-eye images, both of the shutters of the 3D glasses are closed.
The over-drive technology widely used for improving the response time of an LCD display generates an over-drive pixel value according to a pixel value of each of the pixels of a current image and a pixel value of a previous image. The over-drive pixel value is used for driving a corresponding LCD molecule, thus a rotational speed of which becomes faster to improve the response time of the LCD display.
Under normal display circumstances, regardless of whether the display image is updated, a viewer continuously views the display image. Therefore, each of the pixels of the LCD display has a same updating time. FIG. 2 is a schematic diagram of timing of updating pixels of the LCD display under the normal display circumstances. Referring to FIG. 2, for a data enable signal DE, a point “a” represents a data updating time point of a current image corresponding to a pixel cell A of an LCD display, and “a′” point represents a data updating time point of a next image corresponding to the pixel cell A. Similarly, points “b” and “b” of the data enable signal DE respectively represent a data updating time point of the current image corresponding to a pixel cell B and a data updating time point of the next image corresponding to the pixel cell B. The pixel cell A has a time length T1 from the updating time point “a” of the current image to the updating time point “a′” of the next image, and the pixel cell B has the same time length T1 from the updating time point “b” of the current image to the updating time point “b” of the next image. Accordingly, under normal circumstances, pixel cells of the LCD display have a same updating time. However, in the foregoing application of the 3D stereo display, the pair of 3D glasses is only switched to the open state during the VBI as illustrated in FIG. 3. The pixel cell A has a time length T2 from the updating time point “a” of the current image to a 3D glasses open time point “c” within the VBI, and the pixel cell B has a time length T3 from the updating time point “b” of the current image to the 3D glass open time point “c”. In order to gain a preferred display effect, LCD molecules of the pixel cells A and B should turn to desired degrees before the pair of 3D glasses is switched to the open state. That is, the pixel cell A has an updating time of the time length of T2, and the pixel cell B has an updating time of the time length of T3. Therefore, in the application of the 3D stereo display, pixel cells closer to the bottom of the LCD display have shorter updating times. However, in the conventional over-drive technology, each of the pixel cells is supposed to have the same updating time. When the pixel cells are applied to the 3D stereo display, it is unlikely that a good display effect can be obtained.